1m6g
From Proteopedia
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| - | [[Image:1m6g.gif|left|200px]] | + | [[Image:1m6g.gif|left|200px]] |
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| - | '''Structural Characterisation of the Holliday Junction TCGGTACCGA''' | + | {{Structure |
| + | |PDB= 1m6g |SIZE=350|CAPTION= <scene name='initialview01'>1m6g</scene>, resolution 1.652Å | ||
| + | |SITE= | ||
| + | |LIGAND= <scene name='pdbligand=SR:STRONTIUM ION'>SR</scene> | ||
| + | |ACTIVITY= | ||
| + | |GENE= | ||
| + | }} | ||
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| + | '''Structural Characterisation of the Holliday Junction TCGGTACCGA''' | ||
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==Overview== | ==Overview== | ||
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==About this Structure== | ==About this Structure== | ||
| - | 1M6G is a [ | + | 1M6G is a [[Protein complex]] structure of sequences from [http://en.wikipedia.org/wiki/ ]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1M6G OCA]. |
==Reference== | ==Reference== | ||
| - | Conformational and hydration effects of site-selective sodium, calcium and strontium ion binding to the DNA Holliday junction structure d(TCGGTACCGA)(4)., Thorpe JH, Gale BC, Teixeira SC, Cardin CJ, J Mol Biol. 2003 Mar 14;327(1):97-109. PMID:[http:// | + | Conformational and hydration effects of site-selective sodium, calcium and strontium ion binding to the DNA Holliday junction structure d(TCGGTACCGA)(4)., Thorpe JH, Gale BC, Teixeira SC, Cardin CJ, J Mol Biol. 2003 Mar 14;327(1):97-109. PMID:[http://www.ncbi.nlm.nih.gov/pubmed/12614611 12614611] |
[[Category: Protein complex]] | [[Category: Protein complex]] | ||
[[Category: Cardin, C J.]] | [[Category: Cardin, C J.]] | ||
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[[Category: strontium derivative]] | [[Category: strontium derivative]] | ||
| - | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Mar 20 12:39:33 2008'' |
Revision as of 10:39, 20 March 2008
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| , resolution 1.652Å | |||||||
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| Coordinates: | save as pdb, mmCIF, xml | ||||||
Structural Characterisation of the Holliday Junction TCGGTACCGA
Overview
The role of metal ions in determining the solution conformation of the Holliday junction is well established, but to date the picture of metal ion binding from structural studies of the four-way DNA junction is very incomplete. Here we present two refined structures of the Holliday junction formed by the sequence d(TCGGTACCGA) in the presence of Na(+) and Ca(2+), and separately with Sr(2+) to resolutions of 1.85A and 1.65A, respectively. This sequence includes the ACC core found to promote spontaneous junction formation, but its structure has not previously been reported. Almost complete hydration spheres can be defined for each metal cation. The Na(+) sites, the most convincing observation of such sites in junctions to date, are one on either face of the junction crossover region, and stabilise the ordered hydration inside the junction arms. The four Ca(2+) sites in the same structure are at the CG/CG steps in the minor groove. The Sr(2+) ions occupy the TC/AG, GG/CC, and TA/TA sites in the minor groove, giving ten positions forming two spines of ions, spiralling through the minor grooves within each arm of the stacked-X structure. The two structures were solved in the two different C2 lattices previously observed, with the Sr(2+) derivative crystallising in the more highly symmetrical form with two-fold symmetry at its centre. Both structures show an opening of the minor groove face of the junction of 8.4 degrees in the Ca(2+) and Na(+) containing structure, and 13.4 degrees in the Sr(2+) containing structure. The crossover angles at the junction are 39.3 degrees and 43.3 degrees, respectively. In addition to this, a relative shift in the base pair stack alignment of the arms of 2.3A is observed for the Sr(2+) containing structure only. Overall these results provide an insight into the so-far elusive stabilising ion structure for the DNA Holliday junction.
About this Structure
1M6G is a Protein complex structure of sequences from [1]. Full crystallographic information is available from OCA.
Reference
Conformational and hydration effects of site-selective sodium, calcium and strontium ion binding to the DNA Holliday junction structure d(TCGGTACCGA)(4)., Thorpe JH, Gale BC, Teixeira SC, Cardin CJ, J Mol Biol. 2003 Mar 14;327(1):97-109. PMID:12614611
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